For the steel pipes bearing fluid pressure, hydraulic test shall be carried out to test their pressure resistance and quality. If there is no leakage under the specified pressure, or they are qualified. Some steel pipes shall also be subject to crimping test, flaring test and flattening test according to the standard or the requirements of the demander.
In view of the external export difficulties, on the one hand, China's stainless steel industry needs to improve, but it is important for China's stainless steel industry to continuously improve its quality level and comprehensively upgrade.
.Martensitic stainless steels typical martensitic stainless steels include 1Cr13 ~ 4Cr13 and 9Cr18, which have good processing properties. Deep drawing, bending, crimping and welding can be carried out without preheating. 2Crl3 does not require preheating before cold deformation, while 3cr4cr13 is mainly used to make surgical and wear-resistant parts of medical instruments; 9crl8 can be used as corrosion-resistant bearings and tools.
The Chinese brand cold rolled non oriented silicon steel strip (sheet) represents: DW + 100 times of iron loss value (at the frequency of 50Hz, the waveform is sinusoidal, and the magnetic induction peak is 5T per unit weight iron loss value) + 100 times of thickness value. For example, dw470-50 represents cold rolled non oriented silicon steel with iron loss value of 7W / kg and thickness of 0.5mm. Now the new model is represented as 50W470.
.The stainless steel strip is supplied in coils, also known as strip steel. It is divided into hot rolling and cold rolling, as well as ordinary steel strip and high-quality steel strip. There are many kinds of stainless steel belts! Wide use! There are: 201 stainless steel belt, 202 stainless steel belt, 304 stainless steel belt, 301 stainless steel belt, 302 stainless steel belt, 303 stainless steel belt, 316 stainless steel belt, J4 stainless steel belt 309S stainless steel belt, 316L stainless steel belt, 310S stainless steel belt, 430 stainless steel iron belt, etc! Thickness: 0.02mm-4mm width: 5mm-1550mm, can be customized without standard!
L stainless steel pipe is a kind of hollow long round steel, which is mainly used for industrial transmission pipelines and mechanical structural components such as petroleum, chemical industry, medical treatment, food, machinery and instruments, etc. In addition, when the bending and torsional strength are the same, the weight is light, so it is also widely used in all kinds of manufacturing mechanical parts and engineering structures.
At low temperature, coil, strip and tube is guaranteed. The company is professional, timely and cost-effective. It has become the first choice brand for many wire products. Welcome to buy! Ferritic stainless steel tubes have low-temperature brittleness like carbon steel, while austenitic steel does not. Therefore, ferritic or martensitic stainless steels have low-temperature brittleness Austenitic stainless steel or nickel base alloy does not show low temperature brittleness. Sus410 (13Cr), SUS430 of ferritic stainless steel pipe (18cr) and others show a sharp drop in impact value at low temperature. Therefore, it is necessary to pay special attention when using at low temperature. As a way to improve the impact toughness of ferritic series stainless steel, high purification process can be considered. With the help of grade C and N, when the embrittlement temperature is improved in the range of - 50 ℃ to - 100 ℃, it is possible to use it in freezing related projects Sus430lx (18cr Ti, Nb LC) and sus436l (18cr Mo Ti, Nb LC) have been applied to frozen shells. Ferritic stainless steel has a body centered cubic structure. When the material properties become weak, sharp cracks will expand rapidly and cause brittleness. Austenitic stainless steel will not produce brittleness because it has a face centered cubic structure. Austrian stainless steel SUSL (18cr-9ni LC) is used And SUSL (18cr-12ni-2mo-lc) show that they still have superior impact characteristics at low temperature. However, pay attention to the precipitation of ferrite or martensite due to processing, and the tendency of embrittlement due to sensitization and carbide or & sigma; equal heterogeneous precipitation.
Hot rolled stainless steel tubes are generally produced on automatic tube rolling mills. After inspection and removal of surface defects, the solid pipe blank is cut into the required length, centered on the end face of the perforated end of the pipe blank, and then sent to the heating furnace for heating and perforated on the piercer. During perforation, it rotates and advances continuously. Under the action of roll and plug, a cavity is gradually formed inside the pipe blank, which is called rough pipe. Then it is sent to the automatic pipe mill to continue rolling. After that the wall thickness of the whole machine is adjusted, and the diameter is determined by the sizing machine to meet the specification requirements. It is advanced to produce hot rolled seamless steel pipe by continuous pipe mill.
Austenitic stainless steel has good resistance to uniform corrosion, but there are still the following problems in local corrosion resistance: intergranular corrosion of austenitic stainless steel. Austenitic stainless steel will have intergranular corrosion when it is kept warm at 450 ~ 850 ℃ or cooled slowly. The higher the carbon content, the greater the tendency of intergranular corrosion. In addition, intergranular corrosion also occurs in the heat affected zone of the weldment. This is due to the precipitation of Cr rich Cr23C6 on the grain boundary. The chromium poor area is formed in the surrounding matrix, which is caused by corrosion of the primary cell. This intergranular corrosion phenomenon also exists in the ferritic stainless steel mentioned above.
However stainless steel is relative, and it is just ordinary stainless steel. It's better not to use it in a particularly polluted environment. You can rest assured to use stainless steel pipes in your daily life.
Test method.4: stainless steel strip (stainless steel coil): or coil, coil, coil, plate coil. There are many names, and the hardness of the strip varies from dozens to hundreds. The customer needs to determine which hardness to use first. (8K mirror luminosity)
Batch size: a small number of single batch products will affect the unit price.
According to the specification, the specification of stainless steel pipe is mainly based on gb14975-94 stainless steel seamless steel pipe. The general length (indefinite length) of precision stainless steel pipe and thick wall pipe is 5-10m for hot-rolled steel pipe and 1m or more for hot-rolled steel pipe. The wall thickness of cold drawn (rolled) stainless steel pipe is 0.5-0mm and the length is 0-7m; the wall thickness of stainless steel pipe is greater than 0mm and the length is 5-8m.
2. Raw material problem of stainless steel pipe. If the hardness is too low, it is not easy to polish (BQ is not good). If the hardness is too low orange peel is easy to appear on the surface during deep drawing, which affects BQ performance. BQ with high hardness is relatively good.
system.The national standard thickness of stainless steel pipe mainly depends on the thickness of raw materials and processing technology. The thickness of welded pipe is basically the same as that of raw materials. For seamless pipe, it is slightly thinner than that of raw materials. At present, the stainless steel pipe industry is dominated by large negative difference, 0 thickness. It provides all kinds of stainless steel plates, stainless steel coils, stainless steel belts, stainless steel pipes for individuals and enterprises all over the country for a long time, on-site settlement and honest operation. There are offices all over the country for long-term cooperation. Generally, there will be 0.91 ~ 1.
The product quality advantages of continuous casting billet of stainless steel pipe fittings are mainly reflected in that the non grinding rate of the outer surface of the billet except the head and tail section has reached more than 70%, and the total surface grinding yield has reached 915%. In order to achieve this goal, it is necessary to refine the molten steel, achieve low oxygen and sulfur content, do a good job in the metallurgy of the ladle and tundish, accurately determine the molten steel temperature, and realize no oxidation casting, s is the abbreviation of steel, P is the abbreviation of plate, h is the abbreviation of hot heat, and C is the abbreviation of commercial. It generally represents hot-rolled steel plate and strip.
.Production process of hot rolled stainless steel strip / coil: 1. Pickling → 2. High temperature rolling → 3. Process → 4. Annealing → 5. Leveling → ⒍ fine cutting → ⒎ packaging → 8. Reach customers.
According to the specification, the specification of stainless steel pipe is mainly based on gb14975-94 stainless steel seamless steel pipe. The general length (indefinite length) of precision stainless steel pipe and thick wall pipe is 5-10m for hot-rolled steel pipe and 1m or more for hot-rolled steel pipe. The wall thickness of cold drawn (rolled) stainless steel pipe is 0.5-0mm and the length is 0-7m; the wall thickness of stainless steel pipe is greater than 0mm and the length is 5-8m.
When brown rust spots appear on the surface of stainless steel pipes, people will be surprised: & ldquo; Stainless steel pipes are not rusty. Is there a problem with the steel quality;. In fact, this is a one-sided wrong view because the understanding of stainless steel pipe is not comprehensive enough. You should know that stainless steel pipe will rust under certain conditions.